BDanielMayfield wrote:Hello Sally. I think you've made some valid points in questioning conventional wisdom re star formation, especially in areas like the vacinity of Sag A*. However, at least twice in this thread you have claimed that the young star object CX330 changed from a black hole into a protostellar object. Can you provide any support for this claim?

Bruce

Hi Bruce,

First of all, thank you VERY much for considering my debate points and providing consideration even though they are not in a peer-reviewed article.

Thank you for the opportunity to clarify about CX330. I should not have said "black hole". The original observation in 2009 was the detection of an x-ray source. And it's true that x-ray sources are seen as potential candidates for black holes among space scientists, but it is not a confirmed black hole. It was observed giving off some light in additional observations. Then based on data from NASA’s Wide-field Infrared Survey Explorer (WISE) in 2010, the researchers saw that this object had quite a lot of warm dust around it. The research team that has reported on this does NOT see it as discrediting the standard model. They say that it is unusual for being born in a region where there are not other young stars being born. I am the one saying that going from no infrared presence in 2007 to a dust disk with infrared presence in 2010 is contradictory to the standard model.

Thanks for your reply Sally, and may you be happy too. And for amending and clarifying your claims re CX330. I also enjoyed reading the reference from TTU, which shows that more than just UT and TAMU are doing cutting-edge astronomy.

Yes, the protostar ? CX330 did show a remarkable outburst of infrared light over a short period, and it is in a location far from other star forming regions. However, conditions can change rapidly as the collapse of gas in free fall heats up and as radiation from a protostar burns and/or blows openings in its surrounding dust cloud. I would have to agree with the TTU astronomers; this object doesn't 'discredit the standard model' as you put it.

However, to be fair, upon reflection this object doesn't discredit your model either. But, to be honest, I think other facts do.

Bruce

Bruce,

I hear you. I understand your response to the TTU online article. Since they are not saying that the rapid appearance of the protostar is contrary to conventional gravitational collapse models of star formation, it can fit within the usual thinking about gravitational collapse.

According to Wikipedia on Star Formation: "During the collapse, the density of the cloud increases towards the center and thus the middle region becomes optically opaque first. This occurs when the density is about 10^−13 g / cm^3." So the expectation is that the center becomes more dense first, pretty early on, and that heat and radiation will be coming from this center region. I believe that this model for star formation is thought to take millions of years.

The CX330 team called the infrared image of a star in the 2010 image an outburst.

1. What did it burst out from? There was no indication of a star at all in the 2007 image (except for an x-ray source)?

2. I think you will find that a protostar region of gas "in free fall" that has no infrared presence would not be generating x-rays, as in the 2007 image. (However, X-rays are seen as candidates for black holes*)

BDanielMayfield wrote:Hello again sally. I admire your politeness, your interest in the fascinating and challenging subjects of star and planet formation, your statements showing respect for the scientific method, your imagination and your pluck. You're trying to overturn some very well established theories however, and that is a very tall order. For a new theory to gain support it must be a better explanation than previous theories.

Wow! Thank you Bruce for your kindness.

I have paid attention to the history of science on the introduction of new theories, especially Thomas Kuhn's work "The Structure of Scientific Revolutions." And I understand that someone with a new theory has to supply a lot of evidence.

I really appreciate your previous response and this one. You engaged with my ideas and provided thoughtful responses. Thank you very much.

BDanielMayfield wrote:
One of the interesting claims you've made is that gas clouds cannot gravitationally contract on their own, and you've referenced a 1970 Hawking & Penrose statement as proof.

As a point of clarification, I claim that nebulae gas clouds cannot gravitationally collapse on their own, contraction can happen to a certain degree when there is accretion around dense regions withing a big gas cloud. Gravitational collapse is required to achieve fusion. The reasons why gravitational collapse will not happen:
a) coulomb force between atoms
b) the gravitational attraction between gas atoms falls off as the inverse square of the distance.

However, I can see now that I need to know more about the Jeans Criterion and be able to speak to that line of reasoning.

BDanielMayfield wrote:
In the light of that I wondered, what exactly is the currently accepted theory re gravitational collapse of interstellar gas clouds? Here is what I found:

Wikipedia, Jeans instability wrote:In stellar physics, the Jeans instability causes the collapse of interstellar gas clouds and subsequent star formation. It occurs when the internal gas pressure is not strong enough to prevent gravitational collapse of a region filled with matter. ...

I recommend learning about Jeans instability to anyone interested in this topic. It is what could be called the "standard model" of how and why stars form out of interstellar gas.
Is Sally's model better? She has a very tall mountain to climb, I think. I also wonder if Stephen Hawking and Roger Penrose still agree with the 1970 quote.

Bruce

I agree with you on both counts: learning about the Jeans Criterion/Instability being important for the accepted model of star formation, and that I have a very tall mountain to climb.

The reason for Hawking and Penrose saying "The instability of gravitation is not manifest under normal conditions" is "the extreme smallness of the gravitational constant" and "the pull of gravity is readily counteracted by other forces" ...namely the coulomb force between atoms. These have not changed.

I don't have much time right now so I must limit my response to this part of our above exchange:

sallyseaver wrote:

BDanielMayfield wrote:One of the interesting claims you've made is that gas clouds cannot gravitationally contract [collapse] on their own, and you've referenced a 1970 Hawking & Penrose statement as proof.

As a point of clarification, I claim that nebulae gas clouds cannot gravitationally collapse on their own, contraction can happen to a certain degree when there is accretion around dense regions withing a big gas cloud. Gravitational collapse is required to achieve fusion. The reasons why gravitational collapse will not happen:
a) coulomb force between atoms
b) the gravitational attraction between gas atoms falls off as the inverse square of the distance.

The Coulumb Force is very important. It is the force particles see due to electric charges, and so it can be attractive or zero as well as repulsive. Coulumb force causes positive ions to collect electrons and can cause atoms, molecules and dust to clump together if charges are different, and it will not resist gravitational collapse if the particles are cool enough to be non-ionized. This is the reason cool dust clouds are important as places where star formation can begin.